1. Field of the Invention
This invention relates to an apparatus for converting a MUSE (Multiple Sub-Nyquist Sampling Encoding) television signal into a standard television signal.
2. Description of the Prior Art
The MUSE transmission system was proposed for a high-definition television. The number of scanning lines is 1,125 in the high-definition television system while the standard television system has 525 scanning lines. A signal converting apparatus (called "a down converter") has been proposed which converts a MUSE television signal into a conventional standard television signal (typically, NTSC signal) to enable display information of the MUSE television signal to be indicated by a standard television receiver.
The proposed down converter uses intra-field interpolation in processing the transmitted MUSE television signal. Since this intra-field interpolation is rough, a reproduced still picture tends to be contaminated by folding distortion (aliasing noise).